src/test/ui/traits/traits-conditional-model-fn.rs

   1 // run-pass
   2 #![allow(unused_imports)]
   3 // A model for how the `Fn` traits could work. You can implement at
   4 // most one of `Go`, `GoMut`, or `GoOnce`, and then the others follow
   5 // automatically.
   6
   7 // aux-build:go_trait.rs
   8
   9 extern crate go_trait;
  10
  11 use go_trait::{Go, GoMut, GoOnce, go, go_mut, go_once};
  12
  13 use std::rc::Rc;
  14 use std::cell::Cell;
  15
  16 struct SomeGoableThing {
  17     counter: Rc<Cell<isize>>
  18 }
  19
  20 impl Go for SomeGoableThing {
  21     fn go(&self, arg: isize) {
  22         self.counter.set(self.counter.get() + arg);
  23     }
  24 }
  25
  26 struct SomeGoOnceableThing {
  27     counter: Rc<Cell<isize>>
  28 }
  29
  30 impl GoOnce for SomeGoOnceableThing {
  31     fn go_once(self, arg: isize) {
  32         self.counter.set(self.counter.get() + arg);
  33     }
  34 }
  35
  36 fn main() {
  37     let counter = Rc::new(Cell::new(0));
  38     let mut x = SomeGoableThing { counter: counter.clone() };
  39
  40     go(&x, 10);
  41     assert_eq!(counter.get(), 10);
  42
  43     go_mut(&mut x, 100);
  44     assert_eq!(counter.get(), 110);
  45
  46     go_once(x, 1_000);
  47     assert_eq!(counter.get(), 1_110);
  48
  49     let x = SomeGoOnceableThing { counter: counter.clone() };
  50
  51     go_once(x, 10_000);
  52     assert_eq!(counter.get(), 11_110);
  53 }